Charge forming device



July 3, 1956 s. B. SMITH ETAL CHARGE EORMING DEVICE 2 Sheets-Sheet l Filed April 29, 1944 NVENTO'S STANLEY SMIT/'f FRANK C/VDCK x2/@M ATTORNEY July 3, 1956 s. B. SMITH ET A1.

CHARGE FORMING DEVICE 2 Sheets-Sheet 2 Filed April 29, 1944 Arrow/fx United States Patent O CHARGE FURMENG DEVICE Stanley B. Smith and Frank C. Mock, South Bend, lud. Application April 29, 1944, Serial No. 533,296

37 Claims. (Cl. 12S-25) This invention relates to an auxiliary charging system for internal combustion engines and other power units to which it may be adapted, and is particularly concerned with improvements in the so-called water-injection systems by means of which a suitable auxiliary charge component or medium (which may be water, alcohol, liquidsaturated hydrocarbons and like solutions or substances or a mixture thereof) is incorporated in the normal fuelair mixture during the charging operation to modify the action of the charge, as by functioning as a coolant or anti-detonating means, combustion aid, anti-toxic agent or otherwise.

When such systems function as an anti-detonating means for aircraft power units, they usually are active only when the engine is operating in an emergency power range, and to attain this emergency power, there should also be an increase in manifold pressure. Since this increased charging pressure may be safely used only with a wet charge, precaution should be taken to ensure coordinated action of the water metering and boost controls and automatic return of the increased charging pressure to its normal value in the event of failure of the water supply, Also, a fuel-air ratio capable of producing the required power over the normal power range usually requires derichment for the emergency power setting and this should take place concurrently with injection of the auxiliary charge component; and the water or other auxiliary charge component should be admitted to the engine in a predetermined constant ratio to the fuel and simultaneously therewith. Other factors which merit consideration include such degree of automatic operation as will enable the pilot to go into and out of Emergency power and accompanying water injection with a minimum of manual manipulation of controls and detraction from other pressing duties; return of fuel metering as well as charging pressures to previous values in case of failure of parts of the water-injection system or exhaustion of supply of the water or other auxiliary charge component; reliability in operation and simplicity in construction and maintenance.

The present invention includes among its objects to provide a charging system for power units capable of meeting the foregoing requirements and to otherwise improve systems of the auxiliary charge injection type.

Another object is to provide an auxiliary charge injection system which may be readily coordinated, both in structure and in operation, with the power controls which usually constitute part of the power plant of aircraft.

A further object is to provide a system of the type specified particularly adapted for use with an injection carburetor.

The foregoing and other objects and advantages will become apparent in View of the following description taken in conjunction with the drawings, wherein:

Figure 1 is a view in broken side elevation, primarily diagrammatic, of an auxiliary charging system for an internal combustion engine in accordance with the invenice tion coacting with a power control unit and injection type carburetor; and

Figure 2 is a diagrammatic sectional view of the carburetor and auxiliary charging device with the latter relatively enlarged to better show the parts thereof.

Referring to Figure l, an aircraft power unit is illustrated more or less diagrammatically and comprises an engi ne 1d provided with an air-induction conduit 11 including an air scoop or air inlet and having a carburetor installed therein including a main venturi 12, a boost venturi 13 and a throttle 14. Beyond the throttle 14 is a supercharger inlet portion 15, supercharger 16, and supercharger discharge ring 17 adapted to deliver air. and fuel under pressure to the intake manifold or manifold pipes which supply the respective cylinders of the engine. The supercharger as here shown is of the multispeed enginedriven type, the drive being taken from the engine shaft or other rotating part and transmitted to the supercharger rotor through suitable gearing, not shown.

The engine controls are here shown as adapted for either manual or automatic actuation through the medium of a power control unit 18 which in general is of the type disclosed in the copending applications of Frank C. Mock, Serial No. 440,669, iiled April 27, 1942, and now Patent No. 2,453,651, granted November 9, 1948, and 443,042, filed May l5, 1942. Only such parts of this unit are shown and described herein as are necessary to an understanding of how the auxiliary charging system coacts therewith. Briefly, it comprises an outer casing having a main shaft 19 rotatably mounted therein. A lever 20 is secured to the shaft exteriorly of the casing and has pvotallyiconnected thereto link 21 which in turn is pivotally connected to throttle lever 22. Also secured on shaft 19 is a short lever or arm 23 carrying a rotatable spur or pinion gear 24, rotation of arm 23 effecting rotation of lever 20 to variably position the throttle 14. A quadrant 25 is loosely mounted on shaft 19 and has an internally-toothed portion in mesh with pinion 24. Also rotatably or loosely mounted on shaft 19 is a two-segment gear 26 having one segment in constant mesh with pinion 24 and another segment in constant mesh with a toothed rack 27 providing a connection between servo-motor pistons 28 and 29 slidable in cylinders 30 and 31. A spring 32 normally urges the pistons to the left, corresponding to closed throttle position. The gears 24, 25 and 26 form a planetary spur gear train wherein counterclockwise movement of either one or both gears 25 and -26 effects rotation of lever 23, shaft 19 and lever 20 in a counterclockwise `direction and opens the throttle 14, and clockwise movement thereof closes the throttle.

A power control lever 33 may be located in the pilots compartment and connected through link 34 with lever 35 secured on the hub of the quadrant 2S, whereby the pilot is enabled to control the angular position of said quadrant. Mounted on or to rotate with the quadrant 25 are cams 36, 37 and 3&3, the cam 36 setting the manifold pressure datum, cam 37 the supercharger shift datum and cam 38 controlling engine speed.

Cam 36 operates bell crank lever 39 which has a depending arm 39 provided with a fork straddling datum rod 40 and engaging a spring collar for variably loading datum spring 41. A sealed corrugated bellows 42, which may be partially evacuated, is adjustably mounted in a chamber 43 and has its free end secured through a universal connection to the left-hand end of datum rod 40, said bellows being yieldably held against collapse by datum spring 41 and being subjected to engine charging pressure by means of pipe 44 connecting the supercharger ring with the chamber 43 and having a restriction or bleed 45 therein.

Movement of datum rod 40 is transmitted through a pivoted lever 46 to a servomotor control valve 47 provided with a series of lands and grooves and slidable in a cylinder i8 having a series of grooves coacting with the lands and grooves of the valve. A pump 49 (which may be the main oil pump or an auxiliary) supplies oil under pressure to the servo-valve cylinder d through a pipe 50; and from the cylinder d8 oil under pressure is transmitted to servo-motor cylinder 30 through pipe or duct 51 when valve i7 is moved to the left, and to servo-motor cylinder 31 through pipe or duct 52 when valve 47 is moved to the right. Oil may also pass to the interior of casing 18 through pipe or duct 54 having a restriction or bleed 55 therein, and a pipe 56 returns oil from said casing to the pump 49, whereby oil is continuously circulated through the power control unit to prevent congealing of the oil at the low temperatures experienced at high altitudes.

Cam 37 (the supercharger shift datum cam) acts on bell crank lever 57 having a forked arm 57 straddling the left extremity or extension of a cylindrical altitude aneroid valve 58 and contacting an altitude datum sleeve 59 slidable on said cylindrical extension against the tension of datum spring 6ft. The valve 58 is mounted for reciprocation in a bore or cylinder formed in a web 61 which separates an aneriod chamber 62 from the main casing, said chamber 62 being vented to the atmosphere or communicated with scoop pressure and having an altitude aneroid 63 therein which at its right-hand end is xed to the adjacent wall of chamber 62 and at its left-hand or free end has a universal connection through rod 64 with valve 58.

Oil under pressure is communicated from pump 49 to the servo-valve 58 by means of pipe or duct 65, and when said valve is in open position, oil may pass through duct 66 and thence through restriction or bleed 67 to the righthand end of cylinder 68 having a quick-acting shift valve 69 therein. The cylinder 63 has oil under pressure conducted thereto by means of pipe or duct 70 branching olf from pipe 65, and when valve 69 is forced open by oil pressure against the resistance of spring 71, oil passes through pipe or duct 72 into the right-hand end of cylinder I3 and moves valve 74 to the left against the tension of spring 75, whereupon oil may pass through pipe or duct 76 into cylinder 77 having shift piston 78 therein and move said piston to the right against the tension of spring 79 and shift the supercharger change-speed gears through link 80 and shift lever 81.

Provision is also made for manual shifting of the supercharger at any altitude, but a disclosure of means for accomplishing this operation is not necessary for an understanding of the present invention.

Cam 33 is the engine speed or R. P. M. cam, and this acts through lever 82, link 83, lever 84 and propeller speed governor or other propeller pitch control device 85 to vary the pitch of the propeller blades.

It will be seen that by means of a single lever, the pilot is enabled to control the power output with manifold r charging pressure and engine speed automatically conforming to a predetermined schedule as determined by the datum cams 36, 37 and 3S. Thus movement of lever 35 to the right will rotate cam 36 to the left increasing the tension of datum spring 41 so that increased manifold pressure will be required in chamber 43 to hold bellows 42 in its predetermined collapsed condition at the new datum setting. Any tendency of the manifold pressure to vary from hydraulic neutral, or the datum set by the cam 36 and spring 41, results in a correction through lever 45 Vacting on servo-valve 1&7, which will admit high pressure oil either to the left or right-hand servo-motor pistons 28 and 29 and actuate rack 27, the latter acting through gear Z6, shaft 19 and lever 20 to position the throttle; and any change in the setting of cam 36 will be accompanied by a corresponding change in the setting of the supercharger shift cam 37. The design of the altitude aneroid 63 and its coacting datum spring 60 and cam 37 is such that when a critical altitude is reached, at which time the throttle is substantially wide open in order to provide the manifold pressure determined by cam 36, the aneroid valve 5S will begin to open, admitting oil under pressure to the right-hand end of shift valve 69. When this latter valve opens, it admits oil under pressure from line 70 into line 72 and thence to the shiftpiston-valve 7d, which holds back the oil until its pressure is high enough to ensure rapid movement of the shift piston 78.

Fuel is supplied to the engine by a carburetor generally indicated at B. This carburetor is preferably of the pressure feed type operating on the air-fuel pressure differential metering principle in order to most effectively coact with the present improved auxiliary charging system although any carburetor having a source of metering pressure available for pressure communication with the said auxiliary charging system may be utilized. A carburetor of this type is disclosed in the copending application of Frank C. Mock, Serial No. 362,572, led October 24, 1940, and now Patent No. 2,447,261, granted August 17, 1948. Only such parts of the carburetor are herein shown and described as are necessary to an understanding of the present invention.

Referring to the sectional diagram at the top of Figure 2, the carburetor comprises a main casing or housing which, in addition to the main venturi 12, boost venturi 13 and throttle 14 heretofore noted, is provided with air pressure differential chambers 91, 92 and fuel pressure differential chambers 93 and 94. Chambers 91 and 92 are separated by a flexible diaphragm 95, while chambers 93 and 94 are separated by a like diaphragm 96. A rigid wall 97 separates chambers 92 and 93 and also serves to support a fuel-inlet valve 98 adapted to move or reciprocate in relation to the movement of said diaphragms to open a fuel inlet port 99 for admitting unmetered fuel into the chamber 94, from which it flows through conduit or pipe 100 to chamber 101 of a fuel regulator section generally indicated at 102. A throttle-positioned idle valve 103 meters fuel during idling and thereafter is held in its open position as shown in Figure 2.

From chamber 101 unmetered fuel may ilow into the metered fuel section of the fuel regulator and thence by way of pipe or conduit 105i to a discharge nozzle 105, the particular jet or jets through which metering takes place depending upon the position of manual mixture control valve 106 provided with lever 106'; it may pass through automatic lean metering jet 107, automatic rich metering jet 108, power enrichment metering jet 109 and/or power derichment jet 110, the latter being automatically controlled through the auxiliary charging system in a manner to be described. A power enrichment valve 111 is usually provided in carburetors of this type to give added enrichment automatically, generally in the high power range, said valve being actuated by a diaphragm 111 the movement of which is determined by the differential in pressure between metered and unmetered fuel. Metered fuel pressure is communicated back to Chamber 93 by means of ducts 112 and 113, and both chambers 9.3 and 92 are vented of air or vapor by means of ducts 113 and 114, respectively.

Scoop pressure is communicated to chamber 91 by means of impact 'tubes 11S, annular chamber 115 surrounding the main venturi 12, passage 116 controlled by needle valve 117, and thence by way of passage 11S. A mixture control bleed 1.19 leads from the bottom of chamber 91 to chamber 92 said bleed becoming increasingly effective as the pressure in chamber 91 is reduced due to the action of the needle valve 117, the latter being controlled by a density-responsive unit generally indicated at 120. Venturi suction is communicated to chamber 92 by means of a conduit 121.

When the engine is in operation, air is drawn into the air scoop or induction conduit 11 and thence through the venturis 13 and 12 and a differential pressure is created between the throat of venturi 13 and the air inlet which, al QllSiaut entering air density, is proportional to the square of the quantity of air owng. These respective pressures are transmitted to chambers 91 and 92 and create a net force on the diaphragm 35 tending to move the valve 98 to the right, or in a direction to open the valve. If this force were unopposed, the valve would move to the extreme right; however, when the valve opens, fuel under pressure flows into unmetered fuel chamber 94, and to the fuel regulator section 102 where it ows through any one or more of the respective metering orifices and thence through conduit 104 to the discharge nozzle 105, from which it is discharged under a nozzle pressure of, for example, five pounds into the air stream flowing to the engine. Chamber 94 is subjected to unmetered fuel pressure and chamber 93 to metered fuel pressure, and the differential between these respective pressures acts upon the diaphragm 96 tending to move the fuel inlet valve to the left, or in a direction to close the valve, thus opposing the force created on diaphragm 95 by the air differential pressure. The valve will therefore adjust itself to a point of equilibrium such that the differential pressure across the fuel metering orifices is equal to the differential pressure between the air inlet and venturi, whereby constant fuel-air proportioning is maintained. As engine speed is decreased, the rate of air flow through the venturi is decreased thereby decreasing the differential pressures acting on diaphragm 95, causing valve 98 to move towards closed position and thus decreasing the fuel flow to compensate for the decreased rate of air flow. Rate of fuel flow is thus directly controlled by the rate of air flow. Since the venturi to air scoop differential pressure increases for a given rate of mass air ffow, upon a decrease in entering air density, the differential air pressure across diaphragm 95 will tend to increase thereby increasing the fuel flow and richening the mixture. In order to prevent such enrichment with increase in altitude, the calibrated bleed 119 between the chambers 91 and 92 is provided, said bleed being substantially ineffective to vary the pressures in these chambers at such times when the needle valve 117 is in open position, as at ground level, but becoming increasingly effective in reducing the pressure in the chamber 91 as the density-responsive unit 120 acts to move the needle in a direction to progressively restrict passage 113 with increase in altitude. As a consequence, for any given mass air flow the needle valve 117 will so restrict passage 113 with variation in altitude that the differential in pressure across diaphragm 95 remains constant notwithstanding that the differential in the pressures at venturi 13 and impact tubes 115 increases with decrease in entering air density. By this means automatic altitude compensation is obtained and the richness of the mixture is unaffected by variations in altitude.

The auxiliary charging system with which the present invention is concerned is so designed as to cooperate both with the power contror unit 1S and the carburetor 911, and the apparatus which goes to make up the system will now be described.

A water or other auxiliary fluid supply tank 130 of suitable capacity is provided and has a conduit 131 leading therefrom to a water or fluid regulating and metering unit, said conduit having mounted therein a pump 132 and a strainer 133. The pump may be of conventional construction having an in-built by-pass rendered operative when a predetermined delivery pressure is encountered, and is preferably of the electrically-driven type for reasons which will hereinafter appear.

The water pressure regulating and metering unit consists of a main compartmented casing or housing 134 provided with a primary intake chamber 1355 and secondary intake chamber 135', unmetered water pressure chamber 136, metering chamber 137' and outlet or discharge chamber 138. Between the chambers 135 and 135 is a valve 139 which opens against the resistance of an adjustable spring 140 and is provided with a small orifice or jet 139 for a purpose to be described. This valve may be aptly termed a derichment timing valve.

Controlling admission of water from the: chamber to chamber 136 is a pressure regulating valve 141 provided with ports 141' and mounted to reciprocate in a pair of aligned lower and upper seat members 142 and 142. This valve 141 is preferably controlled by some function which is a substantially true index of the fuelair mixture ratio of the fuel charge. As here shown, it is urged toward open position by unmetered gasoline or fuel pressure in fuel diaphragm chamber 143, and toward closed position by the pressure of unmetered water in water diaphragm chamber 143. Accordingly, the valve is provided with a stem 144 urged by a light spring 144 against a ball head 145 engaging in the seat 142', said head being formed on the lower end of a guide rod 146 constituting part of a diaphragm assembly including a water diaphragm 147 and a fuel diaphragm 143, the outer edges of said diaphragms being connected in sealed relation between cap 149, spacer ring 150 and the body of the casing and the central portions thereof being clamped between thin, relatively rigid supporting plates reversely contoured and secured on guide rod 146. The diaphragm chamber 143 is connected to the unmetered fuel system of the carburetor 90 by means of pipe 151.

Pressure of the water in chamber 136 is communicated to a diaphragm chamber 152 and acts on diaphragm 153 which is adapted to engage the stern of an injection control and metering valve 154 mounted in orifice 155, through which metered water flows from chamber 137 and out through ports 155 into chamber 138 when the valve 154 opens against the resistance of adjustable spring 154. A metering jet 156 is located between the chambers 136 and 137. Valve 154 has a specially contoured body coacting with orifice 155 to control metering over a portion of the range of injection, while jet `156 is adapted to control metering during the remainder of the range, as will be more fully hereinafter described.

Valve seat 142 is formed with inlet ports 157, and when valve 139 opens, water passes through these ports and thence down through valve ports 141 and out through flow channel 153 into chamber 136, and it also passes up through port 159 and out into diaphragm chamber 143', the latter communicating with chamber 136 by means of flow channel 159.

A conduit 160 conducts metered water from the discharge chamber 138 to the line 104 leading from the carburetor to the discharge nozzle 1115, said. conduit preferably having a flexible connection therein to minimize vibration. It will be noted that the metered water is directed into the stream of liquid fuel and is discharged with the latter through the nozzle into the air stream. In this manner, advantage is takenof the proved location of the nozzle and its structural characteristics with respect to efficient distribution in connection with the particular engine to which it may be adapted.

Unmetered fuel pressure in the carburetor will always be at a greater pressure by some increment than metered fuel pressure. Thus, if the discharge nozzle 10S is set to deliver at five pounds per square inch, the pressure in diaphragm chamber 94, Figure 2, will be five pounds plus the air metering force resulting from air flow and venturi depression, which may, for example, be one-half pound, making a total of five and one-half pounds, whereas the pressure in diaphragm chamber 93 will be five pounds, or discharge nozzle pressure. Therefore, the water in chamber 136 of the water regulator unit, being at unrnetered fuel pressure will be at a pressure which is always higher than the pressure of the metered fuel in line 104. The spring 144 may be so light as to be negligible as far as its effect on the pressure differential is concerned, its function being simply tot stabilize the action of valve 141. In effect, it balances the weight of the valve with enough overbalance to insure seating of the valve when the unmetered fuel presure in chamber p '7 143 is equal to the unmetered water pressure in chamber 143.

The spring 154' for valve 154 may be set to permit this valve to open at a pressure approximating the differential pressure existing in regulator chambers 91 and 92, or across diaphragm 95, at the beginning of the emergency power range of positions of the pilots control lever, and which differential pressure is proportional to mass air low to the engine and also fuel ilow to the engine.

During operating periods when water is being injected, a leaner fuel-air ratio may be used than would be possible if no water was being injected. In order to produce this derichment during periods of water injection, a fuel derichment valve 161 is provided, said valve controlling the power derichment jet 110. This valve has its stem connected to a diaphragm 162 mounted in a diaphragm chamber 163 which may be placed in pressure communication with water inlet chamber 135 by means of channel 173, chamber 175 and pipe lines 164, 164'. The derichment valve 161 is normally urged to open position by spring 166, this being the position it assumes during normal engine operation, or up until the time water pressure builds up in the chamber 163 suciently to close the valve and injection starts. A bleed 163 communicates diaphragm chamber 163 and line 164, 164 with the top of the water tank through line 167.

A check valve 170 controls or times the admission of unmetered water or water pressure into the pipe or conduit 164 and hence the opening and closing movements of the derichrnent valve; and it also controls or times the increase in manifold or charging pressure, as will be more fully described. This valve 17) is mounted in a seat 171 and has the stem thereof connected to a diaphragm 172 forming a partition between chambers 173 and 173', a valve closing spring 174 being housed in the chamber 173'. A How channel 175 communicates the chamber 135 with the chamber 173, and a port 175' cornmunicates chamber 173' with the chamber 135'. When the water pressure in chamber 135 reaches a predetermined value over and above the pressure in chamber 135', as determined by the pressure drop across jet 139' of valve 139, it exerts suflicient force on diaphragm 172 to open the valve 17u and thereby permit water to pass from chamber 173 through line 164, 164' to the derichment valve diaphragm chamber 163 and close the latter valve. In the event of failure of water supply, or in the event the water is cut off, the check valve 170 will close. A bleed 176 communicates chamber 173 with the line 167.

The water regulating unit and power control unit coact in a manner such that when the pilot moves the power control lever to the emergency position for water injection, the auxiliary charging system is automatically placed into operation while at substantially the same time the manifold pressure is raised to the prescribed value required to most etiiectively produce the increased power output, By referring to Figure l, it will be noted that the lever 35 is provided with an extension 130 having abutment screw 181 adjustably threaded in the lower end thereof, such screw being adapted to contact the switch plunger 182 of a switch 183 and close contacts 184 and 184', which action closes a circuit leading to the water pump 132, said circuit including battery 185, wire 186 leading to contact 184', wire 187 leading from contact 184 to one of the terminals of the water pump motor, and wire 18S leading from the other terminal of said motor back to the battery.

When the differential in the pressures in chambers 135 and 135' across valve 139 of the water regulator unit attains a certain predetermined value and operates the check valve 170, water under pressure passes through pipe 189 to a pressure switch cylinder 190 where it acts on contact member 190 and moves the latter into closing position with respect to contacts 191, 191', closing the circuit to a solenoid valve 192, controlling communication of pressure from the supercharger intake portion of the air induction conduit through pipe line 193, valve chamber 194 and pipe 193', having a pressure-stabilizing bleed 193a therein, to the aneroid chamber 43. When the solenoid valve 192 is energized, it opens, and relatively low pressure air from the supercharger inlet is bled into chamber 43 through calibrated restriction 45, and pressure of a lower value than that then prevailing in aneroid chamber 43 is established in aneroid chamber 43, thereby requiring an increase in charging pressure to maintain the bellows in its previous collapsed state against the pull of datum spring 41. This operation is similar to the action of the cam 36 when the latter is rotated to the left to increase the charging pressure datum, but further rotation of this cam due to movement of the power lever to emergency or water injection position does not increase the datum on spring 41 since the cam is contoured to have no effect on lever 39 during this range of power lever movement, the increase in datum being accomplished by lowering the pressure in chamber 43 as above indicated. The reason for this is that should the water fail, the decreased pressure acting through switch cylinder 191) will open the circuit to the solenoid valve and the latter in turn will close, thereby permitting the pressure in aneroid chamber 43 to return to the value existing prier to wet charge injection. This is a safety feature of importance, since harm might result in a relatively short time should a dry lean charge be injected into the engine with the high manifold pressure permissible with a wet charge.

The system operates substantially as follows:

Assuming the pilot desires to go into emergency or Water injection power, he moves lever 33 (Figure 1) to a position such as to rotate the lever 35 to a point where the Contact 181 engages switch plunger 182, thereby closing the circuit to the water pump 132. When the pump starts and builds up pressure in chambery water begins to ow through oriiice 139' into chamber 135'. At this time, the pressure in chamber 136 is lower than that existing in the unmetered fuel conduit 100, and as a consequence, the valve 141 is open due to the pressure existing in diaphragm chamber 143; and unmetered water iiows into the chamber 136 and also into water diaphragm chamber 143' and continues flowing until the pressure in said latter chamber overcomes unmetered fuel pressure in chamber 143, whereupon the valve 141 closes; this action continuing as one pressure overbalances the other as long as the system is in operation, and hence the water in chamber 136 is maintained substantially at unmetered fuel pressure.

The water in chamber 136 also passes to diaphragm chamber 15?. where it acts on diaphragm 153 and opens valve 154. Since the spring 154' of valve 154 has been set to resist pressures up to a pressure approximating the differential across diaphragm 95 of the regulator chambers 91 and 92 which exists when mass air flow through the carburetor conforms to a predetermined emergency power setting, valve 154 will remain closed until the unmetered water in chamber 136 attains a pressure approximatin" the unmetered fuel pressure existing at this point on the power curve.

As valve 154 opens, upon power increasing movement of the pilots control lever, its movement will be more or less gradual, since the unmetered water pressure will gradually overcome the pressure of spring 154', and due to the gradual taper of the body of said valve, a metering action will take place through orifice which will control metering until the ilow through orifice 155 approximates the ow capacity of orifice 156, whereupon the latter becomes the principal metering restriction. Conversely, as the power control lever 33 is moved back to a normal power setting, valve 154 will close, and during its closing movement, metering will be resumed through orice 155.

Metered water in discharge chamber 138 ows by way of line 161i to the line 104 conducting metered gasoline 9 from the carburetor to the spray nozzle 105; and injection begins.

The pressure drop across iet 139 of valve 139 determines the pressure differential in chambers 135 and 135', which in turn determines the time of opening and closing of valve 170 and hence the time of closing and opening of the derichment valve lol. By properly adjusting the tension of valve spring llll, this dierential may in turn be adjusted to a point where the derichment valve will close only when the rate at which water is being introduced into the induction passage exceeds some predetermined minimum, and will remain closed only so long as the rate of water introduction equals orexceedsthis minimum rate.

When check valve f7@ opens, water under pressure is conducted to diaphragm chamber 163 of derichment valve 161, thereby closing the derichment jet 110. This reduces the richness of the charge and results in a mixture designed to produce maximum power without detonation and also with economy in fuel consumption.

Since the water is metered at a differential pressure substantially equal to the pressure differential between metered and unmetered fuel, it will be injected into the system in constant ratio to fuel flow; and since this differential is governed primarily by the mass flow of air to the carburetor, the auxiliary charge component is also injected in proportion to the fuel-air mixture. The water is metered accurately throughout the entire range of injection.

In the event of failure of the water supply, not only will the manifold pressure return to the value previously set by the datum cam 36, but the derichment valve 161 will also open and the carburetor will then function normally on the basis of a dry charge.

The switch indicated at 200 illustrates an example of what may be termed a master control switch. It may be used in place of the switch 183 as an automatic control operated by means of oil pressure inthe servo system or by means of air or fluid pressure in the air-fuel supply system, or it may be used in conjunction with the switch 183 and in series therewith. In the example shown, it is actuated by means of oil pressure in the supercharger shift part of the servo system, the line 201 being branched off from the line 72 and connecting at its terminus with the said switch 200, so that when oil is forced through the line 72, 72' to the shift piston 73 the switch 200 is actuated. By placing this master control switch in series with the switch l and between the battery and said latter switch, the main electric circuit would be inopera-` tive as long as the master control switch were open, or until such time as the supercharger were shifted to a higher speed ratio, whereupon the main circuit would be placed in condition for operation through lever 85 and switch 183. When used in this manner, the solenoid valve` 192 and coacting pressure line to the aneroid 42 may be dispensed with if desired, although the safety factor provided by this latter valve would not bepresent. However, the pump circuit would in such a case be locked out until such time as the supercharger is shifted into high blower, whereupon the circuit would be in condition for automatic operation when the power lever 35 is moved to emergency power position.

Other modifications and rearrangements of parts in connection with the primary fuel supply and auxiliary fuel system will be apparent to those skilled in the art from the foregoing description taken in conjunction with the drawings, and it should therefore be understood that the invention is not limited to the particular embodiment disclosed nor otherwise than in accordance with the appended claims.

We claim:

l. For use with an engine having an air-fuel intake system including means for injecting metered primary fuel under pressure into the engine, an auxiliary chargeinjection system for metering an auxiliary charging fluid to the primary fuel including a chamber for unmetered auxiliary fluid, a valve controlling admission of the fluid to said chamber, means responsive to a function of the air-fuel intake system controlling said valve to maintain the unmetered fluid in said chamber at a pressure higher by a certain constant value than the pressure of the metered primary fuel, another valve in series with said rstnamed valve controlling the admission of the auxiliary charging fluid to the metered primary fuel, metering means associated with said second-named valve and rendered operative upon opening of the valve, and means responsive to the pressure of the unmetered fluid in said chamber controlling said last-named valve.

2. For use with an engine having a fuel supply system including an air intake provided with a venturi for measuring the quantity of intake air and means for supplying a primary liquid fuel under pressure to the air intake having metering means operating in relation to the differential between venturi air flow and liquid fuel How, auxiliary charge-injecting apparatus for metering an auxiliary charging fluid to the primary fuel including a chamber for unmetered auxiliary fluid, a valve controlling admission of fluid to said chamber, means responsive to the pressure of unmetered primary fuel and unmetered auxiliary fluid controlling said valve to maintain the pressure in said chamber at a value approximating unmetered primary fuel pressure, another valve in series with said first-named valve controlling admission of the auxiliary fluid to the metered primary fuel, metering means associated with said latter valve and rendered operative upon opening of said valve, and means responsive to the pressure of the unmetered auxiliary fluid in said chamber controlling said last-named valve.

3. For use with an engine having a fuel supply system including an air intake and `means for supplying a stream of primary fuel under pressure to said intake, a device for injecting an auxiliary `charging lluid into the stream of primary fuel including a valve controlling injection of the fluid, a metering orifice controlled by said `valve and rendered operative upon opening of the valve, a chamber for unmetered fluid, means for supplying fluid to said chamber at a pressure higher than the pressure of the stream of primary fuel, and means responsive to the pressure of the fluid in said chamber controlling the opening and closing movements of said valve. 4. For use with an engine having a fuel supply system including an air intake and means for supplying a stream of liquid primary fuel under pressure to said intake metered in relation to the pressure differential between air flow and fuel llowpa device for injecting an auxiliary charging fluid into the stream of primary fuel including a valve controlling injection of the fluid, metering means associated with said valve and rendered operative upon opening of the valve, t pressure-responsive means for actuating said valve, a chamber for unmetered fluid in pressure communication with said last-named means, a

` valve controlling admission of unmetered fluid to said chamber, and pressure-responsive means for actuating said latter Valve subjected in an opening direction to the pressure of unmetered primary fuel and in a closing direction to the pressure of unmetered fluid in said chamber and whereby the pressure in said chamber is maintained at a value approximating the pressure of the unmetered primary fuel.

5. For use with a charge-forming device having airfuel pressure differential fuel metering system and means for delivering a stream of metered primary fuel to the air-intake of an engine, a device for injecting an auxiliary charging fluid into the stream of primary fuel at a `predetermined point in the power curve including a valve controlling the time or point of injection, fluidmetering means rendered operative upon opening of said valve, a diaphragm operatively connected to said valve to open the latter, and means for subjecting said diaphragm to the pressure of a predetermined unmetered fuel pressure including a chamber for' unmetered fluid in pressure-communication with said diaphragm, a valve controlling admission of unmetered iluid to said chamber and `means responsive to a function of the air-fuel pressure diiferential system controlling said latter valve.

6. For use with a charge-forming device having air-fuel pressure differential fuel metering means and a conduit for delivering a stream of metered primary fuel to the air intake of an'engine, an auxiliary charge injection system for metering an anti-detonating fluid to the metered primary fuel including, a valve controlling the point or time on the power curve at which said fluid is injected, uuid-metering means rendered operative upon opening of said valve, a spring urging said valve toward closed position and a diaphragm urging the valve toward open position, a chamber for unmetered fluid having pressure communication with said diaphragm, a valve controlling admission of unmetered fluid into said chamber, diaphragm means controlling said latter valve, said diaphragm means being subjected on its valve-opening side to the pressure of unmetered primary fuel and on its closing side to the pressure of unmetered anti-detonating lluid and whereby the fluid in the chamber is maintained at a pressure approximating that of the 'unmetered primary fuel to thereby insure metering of the anti-detonating iluid iu constant ratio to fuel flow.

7. In combination, a charge-forming device or carburetor having a fuel-metering system provided with a plurality of metering jets including a derichment jet and means for controlling the ilow of a primary fuel through said jets to an engine, an auxiliary charge-injection system for supplying an auxiliary charge component such as an anti-detonating iluid to the engine including means for metering said fluid under pressure into the primary fuel system at a predetermined point in the power curve,`

a derichment valve coacting with said derichment jet, means maintaining said valve in open position during normal engine operation, and means responsive to the pressure of the fluid in the auxiliary charge-injection system for closing said valve and deriching the normal fuel charge upon injection of the anti-detonating iluid.

8. ln combination, a charge-forming device or carburetor having fuel metering means including a jet or port constituting when open part of the normal metering system and when closed functioning to reduce the richness of the primary fuel charge, a derichment valve coacting with said jet, an auxiliary charge-injection system for suppling an auxiliary charge component such as an anti-dctonating uid to the metered primary fuel including means for metering said fluid under pressure into the primary fuel system at a predetermined point in the power curve, means maintaining said valve open during normal engine operation when primary fuel only is being supplied to the engine, means responsive to pressure of the fluid in the auxiliary charging system for closing said valve, and means for timing the admission of operating pressure to said valve in relation to the time of injection of the said fluid. t

9. In combination, a charge-forming device or carburetor having fuel metering means including a jet or port constituting when open part of the normal metering system and when closed functioning to reduce the richness of the primary fuel charge, a derichment valve coacting with said jet, an auxiliary charge-injection system for supplying an auxiliary charge component such as an anti-detonating iluid to the metered primary fuel including means for metering said iluid under pressure into the primary fuel system at a predetermined point in the power curve, means maintaining said valve open during normal engine operation when primary fuel only is being supplied to the engine, pressure-responsive means for closing said valve, and means for communicating operating pressure from the auxiliary system to said valve including a valve arranged to open when a certain pressure is attained in said auxiliary system.

10. In combination, a charge-forming device or carburetor having fuel metering means including a jet or port constituting when open part of the normal metering system and when closed functioning to reduce the richness of ythe primary fuel charge, a derichment valve enacting with said jet, an auxiliary charge-injection system for supplying of an auxiliary charge component such as an anti-detonating iluid to the metered primary fuel including means for metering said iluid under pressure into the primary fuel supply system at a predetermined point in the power curve, means maintaining said valve open during normal engine operation when primary fuel only is being supplied to the engine, a member responsive to pressure for closing said valve, a conduit for communicating operating pressure from the auxiliary system to said member, a valve controlling said conduit, and means for timing the opening of said latter valve in relation to the pressure of fluid in the auxiliary system.

l1. in combination, a charge-forming device or carouretor having'fuel metering means including a jet or port constituting when open part of the normal metering system and when closed functioning to reduce the richness of the primary fuel charge, a derichment valve coacting with said jet, an auxiliary charge-injection system for supplying an auxiliary charge component such as an anti-detonating fluid to the metered primary fuel including means for metering said fluid under pressure into the primary fuel-supply system at a predetermined point in the power curve, means maintaining said valve open during normal engine operation when primary fuel only is being supplied to the engine, a member responsive to pressure of the fluid in the auxiliary system for closing said valve, a conduit for communicating pressure to said member, a valve controlling admission of fluid to said conduit, said latter valve having an actuating member subjected to the iluid in the auxiliary system and arranged to open the valve when the fluid lattains a predetermined pressure.

l2. In combination, a charge-forming device or carburetor having fuel metering means including a jet or port constituting when open part of the normal metering system and when closed functioning to reduce the richness of the primary fuel charge, a derichment valve coacting with said jet, an auxiliary charge-injection system for supplying an auxiliary charge component such as an anti-detonating iluid to the metered primary fuel including means for metering said iluid under pressure into the primary fuel-supply system at a predetermined point in the power curve, means maintaining said valve open during normal engine operation when primary fuel only is beingy supplied to the engine, a member responsive to pressure of the fluid in the auxiliary system for closing said valve, a conduit for communicating pressure to said member, a valve controlling admission of iluid to said conduit, said latter valve having an actuating member subjectedV to the iluid in the auxiliary system and arranged to open the valve when the iluid attains a predetermined pressure, and a timing valve arranged to open under predetermined pressure and admit lluid into the auxiliary system, said latter valve being provided with a jet adapted to produce a differential pressure on said actuating member which differential governs the opening and closing movement of said second-named valve.

13. In combination, an engine having an air-fuel supply system including an air-intake provided with an intake manifold and a charge-forming device or carburetor for supplying a primary fuel in relation to the supply of air and means for regulating the charging pressure in said manifold, an auxiliary charge-injection system for supplying an auxiliary charge component such as an anti-detonating iluid to the engine including means for admitting said fluid intov the primary fuel-supply system at a predetermined point in the power curve, means 13 for increasing the charging pressure to conform to the modified fuel charge resulting from injection of said fluid, and means for automatically returning the charging pressure to the valve previous to such increase in the event of failure of the auxiliary fluid supply.

14. In combination, an engine having an air-fuel supply system including an air-intake provided with an intake manifold and a charge-forming device or carburetor for supplying a primary fuel in relation to the supply of air, an auxiliary charge-injection system for supplying an auxiliary charge component such as an anti-detonating fluid to the metered primary fuel including means for admittinU said fluid into the primary fuel supply system at a predetermined point in the power curve, variable datum means for regulating the charging pressure in said manifold, means coacting with said variable datum means for increasing the charging pressure upon injection of the fluid, and means for automatically returning the charging pressure to the value previous to such increase in the event of failure of the auxiliary system.

15. In combination, an engine having an air-fuel supply system including an air-intake provided with an intake manifold and a charge-forming device or carburetor for supplying a primary fuel in relation to the supply of air, means for boosting the pressure of the charge in said manifold, a variable boost control for automatically regulating the manifold pressure, a power lever for said control, an auxiliary charge-injection system for supplying an auxiliary charge component such as an anti-detonating fluid to the engine, and means rendered operative by movement of said lever to a predetermined power position for increasing the charging pressure to a value above that Which would normally be obtained by adjustment of the boost control by said lever to conform to the modified fuel charge resulting from injection of said fluid.

16. In combination, an engine having an air-fuel supply system including an air-intake provided with an intake manifold and a charge-forming device or carburetor for supplying a primary fuel in relation to the supply of air, means for boosting the pressure of the charge in said manifold, a variable boost control for automatically regulating the manifold pressure, a power lever for said control, an auxiliary charge-injection system for supplying an auxiliary charge component such as an anti-detonating fluid to the engine, means rendered operative by movement of said lever to a predetermined power position increasing the charging pressure to conform to the modified fuel charge resulting from injection of said fluid, and means independent of said lever automatically returning the charging pressure to the value prevailing previous to such increase in the event of failure of the auxiliary fluid supply.

17. In combination, an engine having an air-fuel supply system including an air-intake provided with an intake manifold and a charge-forming device orcarburetor for supplying a primary fuel in proportion to the supply of air,`

means such as a supercharger for boosting the charging pressure in said manifold, a variable boost control, an auxiliary charge injection system for supplying an auxiliary charge component such as an anti-detonating fluid to the engine including means for metering said fluid under pressure into the primary fuel supply system at a predetermined point in the power curve, means responsive to pressure in the auxiliary system for automatically increasing the charging pressure to a value consistent with the modified fuel charge resulting from injection of said fluid, the charging pressure automatically returning to the value prevailing previous to such increase upon a drop in pressure beyond a certain value in the auxiliary fluid supply.

18. In combination, an engine having an air-fuel supply system including an air-intake provided With an intake manifold and a charge-forming device or carburetor for supplying a primary fuel in proportion to the supply of air, means such as a supercharger for boosting the charging pressure in said manifold, a power control unit provided with variable datum means for controlling the charging pressure including a cam for adjusting and setting the datum, an auxiliary charge-injection system for supplying an auxiliary charge component such as an antidetonating fluid to the engine including means for metering said fluid under pressure into the primary fuel supply system at a predetermined point in the power curve, means responsive to pressure in the auxiliary system for automatically increasing the charging pressure beyond the range of the cam to conform to the modified fuel charge resulting from injection of said fluid, the charging pressure automatically returning to the value set by said cam in the event of failure of the auxiliary fluid supply.

19. In combination, an engine having an air-fuel supply system including an air-intake provided with an intake manifold and a charge-forming device or carburetor for supplying a primary fuel in proportion to the supply of air, means such as a supercharger for boosting the charging pressure in said manifold, variable datum means for regulating the charging pressure including a device responsive to pressure in said manifold, an auxiliary chargeinjection system for supplying an auxiliary charge com ponent such as an anti-detonating fluid to the engine including means for metering said fluid under pressure into the primary fuel supply system at a predetermined point on the power curve, and means responsive to pressure in the auxiliary system for modifying the action of said pressure-responsive device to automatically increase the charging pressure datum to conform to the modified fuel charge resulting from the injection of said fluid.

20.` In combination, an engine having an air-fuel supply system `including an air-intake and a charge-forming device or carburetor for supplying a primary fuel in proportion to the supply of air, variable datum means including a pressure-responsive device for regulating engine charging pressure, an auxiliary charge-injection system for supplying an anti-detonating fluid to the engine including means for metering said fluid under pressure into the primary fuel supply system at a predetermined point in the power curve, means including a conduit for communicating fluid pressure to said device acting to increase the charging pressure datum in accordance with the modified fuel charge resulting from injection of said fluid, a valve controlling said conduit, and means responsive to pressure in said auxiliary system for controlling said valve.

21. In combination, an engine having an air-fuel supply system including an air-intake provided with an intake manifold and a charge-forming device or carburetor for supplying a primary fuel in proportion to the supply of air, variable datum means including a pressure-responsive device having pressure communication with said manifold for regulating engine charging pressure, a powercontrol lever, an auxiliary charge-injection system for supplying an auxiliary charge component such as an antidetonating fluid to the engine including means for metering said fluid under pressure into the primary fuel supply system at a predetermined point in the power curve determined by the setting of said lever, means including a conduit for communicating fluid pressure to said device acting to increase the charging pressure datum in accordance with the modified fuel charge resulting from injection of said fluid, an electrically operated valve coacting with said conduit, and an electric circuit operatively interconnecting said lever, auxiliary system and valve including a switch adapted to close the circuit when th lever is moved to auxiliary charge injecting positionu 22. In combination, an engine having an air-fuel supply system including an intake manifold and a charge-forming device or carburetor for supplying a primary fuel in proi,

portion to the supply of air and means for boosting the charging pressure in said manifold, said carburetor including a jet or port constituting when open part of a normal metering system and when closed functioning to reduce the richness of the primary fuel charge, a derichment valve coacting with said jet, a variable-datum boost control for automatically regulating the manifold pressure, an. auxiliary charge injection system for supplying an auxiliary charge component such as an anti-detonating fluid to the engine including means for admitting said fluid into the primary fuel supply system at a predetermined point in the power curve, said derichment valve being open during normal engine operation when primary fuel only is being supplied to the engine, a member responsive to pressure for closing said valve, means responsive to pressure in the auxiliary system for increasing the charging pressure datum to conform to the modified fuel charge resulting from injection of said fluid and means for simultaneously conducting pressure to said derichment valve actuating member to close the latter.

23. In combination, an engine having an air-fuel supply system including an air-intake provided with an intakemanifold and a charge-forming device or carburetor for supplying a primary fuel in proportion to the supply of air, means for boosting the charging pressure in said manifold, a variable-datum boost control for automatically regulating the manifold pressure including a power lever, said carburetor including a jet or port constituting when open part of the normal metering system and when closed functioning to reduce the richness of the primary fuel charge, a derichment valve coacting with said jet, and an auxiliary charge injection system for supplying an auxiliary charge component such as an anti-detonating fluid to the engine including means for metering said uid under pressure under the primary fuel system at a predetermined point in the power curve, means maintaining said derichment valve open during normal engine operation when primary fuel only is being supplied to the engine, a member responsive to pressure in the auxiliary system for closing said valve, means also responsive to pressure in the auxiliary system for increasing the charging pressure datum to conform to the modified fuel charge resulting from injection of said uid, and means for starting the auxiliary system automatically when the power lever is moved to a position demanding auxiliary fuel injection.

24. In combination, an engine having an air-fuel supply system including an air-intake provided with an intake manifold and a charge-forming device or carburetor for supplying primary fuel in proportion to the supply of air, means for boosting the charging pressure in said manifold, a variable datum boost control including a device such as an aneroid responsive to pressure in said manifold, said carburetor having fuel metering means including a jet or port constituting when open part of the normal metering system and when closed functioning to reduce the richness of the primary fuel charge, a derichment valve coacting with said jet, an auxiliary charge injection system for supplying an auxiliary charge component such as an anti-detonating uid to the engine including means for metering said liuid under pressure under the primary fuel supply system at a predetermined point in the power curve, means maintaining said derichment valve open during normal operation when primary fuel only is being supplied to the engine, a member responsive to pressure in the auxiliary system for closing said valve, means for conducting a pressure of reduced value to said aneroid to increase the charging pressure datum to conform to the modified fuel charge resulting from said fluid, a valve controlling admission of datum-increasing pressure to said aneroid, and means for substantially simultaneously conducting pressure to said derichment valve actuating member and said charge datum increasing valve when the auxiliary system is initially placed in operation, a failure of pressure in said auxiliary system resulting in opening of said derichment Valve and a reduction in charging pressure to normal value.

25. A fluid regulating and metering unit adapted for use with an airplane engine to meter an auxiliary charge component such as an anti-detonating uid into the primary fuel supply, comprising a casing having a iiuid inlet chamber, a metering head chamber, a valve controlling admission of fluid from said inlet chamber to said meterj y 16 ing head chamber, pressure-responsive means for moving said valve toward both open and closed positions, a relatively light spring balancing said valve, a discharge and metering valve spring-pressed toward closed position controlling flow of fluid from the metering head chamber to the discharge side of the unit, means responsive to the pressure of the fluid in the metering head chamber for opening said discharge and metering valve, and metering means associated with said latter valve and rendered operative when the valve is open.

26. A fluid regulating and metering unit adapted for use with an airplane engine to meter an auxiliary charge component such as an anti-detonating fluid into the primary fuel supply, comprising a casing having a primary intake chamber, a secondary intake chamber, metering head chamber, metering chamber and an outlet or discharge chamber, a valve spring-pressed toward closed position controlling admission of fluid from said primary to said secondary inlet chamber and having a bleed therein adapted to establish differential pressures in said primary and secondary inlet chambers, a check valve for communicating fluid pressure from the auxiliary system to the main fuel-supply system having an actuating member subjected to the resultant of the differential pressures, a valve controlling admission of iiuid from said secondary inlet chamber to said metering head chamber, pressure-responsive means for controlling said latter valve to maintain a predetermined constant metering head in said latter chamber, a discharge and metering valve controlling ow of fluid from the metering head chamber to the said outlet chamber having a member responsive to the metering head pressure for controlling the time of opening and closing thereof, and metering means associated with said latter valve and rendered operative when the valve is open.

27. In combination, an engine having an air-fuel supply system including a throttle-controlled induction passage provided with a carburetor for supplying fuel in proportion to the supply of air, a power-control unit including variable datum means and a coasting servo-controlled fluid pressure system for variably positioning said throttle to regulate the charging pressure, an auxiliary chargeinjection system for supplying an auxiliary charge component such as an anti-detonating fluid to the engine including means for metering said fluid under pressure into the primary fuel supply system at a predetermined point in the power curve, and means responsive to pressure in the servo system for controlling the auxiliary system.

28. In combination, an engine having an air-fuel supply system including a throttle-controlled induction passage provided with a multiple-step supercharger, an intake manifold and a carburetor for supplying fuel in proportion to the supply of air, a power-control unit including variable datum means and a coacting servo-controlled iluid pressure system for variably positioning said throttle to regulate the charging pressure and to also effect shifting of the supercharger step, an auxiliary charge-injection system for supplying an auxiliary charge component such as an anti-detonating fluid` to the engine including means for metering said fluid under pressure into the primary fuel supply system at a predetermined point in the power curve, said latter means including an electrically operated pump, an electric circuit operatively connecting the power unit with the auxiliary system including a pressure switch, and means for transmitting pressure from said servo system to said switch, the arrangement being such that switch-v actuating pressure becomes effective when the supercharger is shifted to high blower.

29. In combination with a charge-forming device having an air-fuel pressure differential fuel metering system and a conduit for delivering a stream of metered primary fuel to the air intake of an engine, an auxiliary chargeinjection system for supplying an anti-detonating fluid to the engine including a valve controlling the point or time on the power curve at which said fluid is injected, fluid-metering means rendered operative upon opening of said valve, a spring urging said valve toward closed position and a diaphragm urging the valve toward open position, a chamber for unmetered fluid having pressure communication with said diaphragm, a valve controlling admission of unmetered fluid into said chamber, diaphragm means controlling said latter valve, said diaphragm means being subjected on its valve-opening side to a pressure emanating in and variable as a function of the air-fuel pressure differential system and on its closing side to the pressure of unmetered anti-detonating fluid.

30. In a fuel and auxiliary charging fluid supply system for an engine having means for metering a primary fuel to the engine under pressure including a fuel metering jet constituting when open part of the normal metering system and when closed resulting in a reduction of the richness of the fuel charge, means for supplying an auxiliary charging fluid to the engine including a ow passage having a metering restriction therein, means for automatically regulating the metering head across said latter restriction as a function of the primary fuel metering pressure, a valve downstream of said automatic regulating means for controlling the ow of uid through said second-named restriction, a derichment valve for controlling said fuel metering jet, pressure responsive means connected to said derichment valve, and means for communicating lluid pressure to said pressure responsive means to close said derichment valve when said first-named valve is opened to establish a flow of fluid through said secondnamed restriction.

31. In combination, a charge forming device or carburetor having a fuel metering system provided with a plurality of metering jets including a derichment jet and means for controlling the ow of primary fuel through said jets to an engine, an auxiliary charge injection system for supplying an auxiliary charge component such as an antidetonating uid to the engine having means for metering the fluid under pressure for admixture with the primary fuel supply, a derichment valve coacting with saidv derichment jet, a derichment valve control valve, and means responsive to changes in pressure of the fluid in the auxiliary charge injection system for actuating said derichment valve control valve.

32. In combination, a charge forming device or carburetor having fuel metering means including a derichment jet or restriction constituting when open part of the normal fuel metering system and when closed serving to reduce the richness of the primary fuel charge, an auxiliary charge injection system for supplying an auxiliary charge component such as an antidetonating uid to the engine including means for metering uid under pressure for admixture with the primary fuel supply, a derichment valve coacting with said derichment jet, a derichment valve control valve, and means responsive to the drop across said metering means for actuating said latter valve.

33. For an engine having manifold pressure regulating means and a water or other liquid injection system, an automatic regulator including: a manually actuated control lever; rst pressure responsive bellows, and a passage through which the first bellows may be subjected to engine manifold pressure; second pressure responsive bellows, and a passage through which the second bellows may be subjected to a pressure which tends to vary with changes of altitude; third pressure responsive means, and a passage through which the third means may be subjected to a pressure which increases upon occurrence of water injection; and power means under the control of said irst and second pressure responsive bellows and third pressure responsive means for actuating the manifold pressure regulating means.

34. For use with an engine having an anti-detonant injection system, an automatic control device including: manifold pressure responsive means; additional pressure responsive means sensing changes of a pressure tending to vary with the altitude; third means actuated upon injection of anti-detonant; and power means controlled by said three means to control the engine fuel supply.

35. For use with an engine having an anti-detonant injection system, an automatic control including: engine manifold pressure responsive means; additional pressure responsive means sensing changes of a pressure which varies with the altitude; third means actuated upon antidetonant injection; regulating means for controlling the engine fuel supply; and an operative connection including levers and a hydraulic power system to actuate said regulating means from said manifold pressure responsive means, additional pressure responsive means and third means.

36. For use with an engine having a combustion chamber, a system of passages leading combustion air to the combustion chamber and discharging combustion gases therefrom, a fuel supply system, and an injection system for supplying the engine with a uid tending to lower engine operating temperatures under high load conditions; an automatic control device including: rst pressure responsive means; a passage for connecting the first pressure responsive means with said system of passages; second pressure responsive means; a passage for subjecting said second means to a pressure tending to vary with the altitude; third pressure responsive means; a passage for subjecting said third means to a pressure which varies as said uid is being injected; and power means controlled by said three pressure responsive means to regulate the engine fuel supply.

37. Apparatus for controlling the fuel supply of a combustion engine having an air induction passage, a fuel supply system and an auxiliary uid supply system; said apparatus comprising a power system for variably regulating the engine fuel supply; first pressure responsive means adapted for connection with. said air induction passage to be constantly exposed to the pressure therein; second pressure responsive means for sensing changes of a pressure tending to vary with the altitude; third means actuated during actual supply of auxiliary fluid to the engine; and means in said power system for actuating the latter to alter the engine fuel supply automatically in predetermined relation to movements of said rst, second and third means.

References Cited inthe le of this patent UNITED STATES PATENTS Re. 22,447 Hersey et al Feb. 29, 1944 2,031,527 Dodson Feb. 18, 1936 2,217,364 Halford et al. Oct. 8, 1940 2,311,828 Hansen Feb. 23, 1943 2,337,982 Ericson Dec. 28, 1943 2,392,565 Anderson Jan. 8, 1946 2,491,484 Dolza et al Dec. 20, 1949 FOREIGN PATENTS 429,682 Great Britain 'June 4, 1935 523,895 Great Britain July 25, 1940 547,902 Great Britain Sept. 16, 1942 

